S H 

icy 



U. S. COMMISSION OF FISH AND FISHERIES, 

GEORGE M. BOWERS. Commissioner. 



ARTIFICIAL PROPAGATION 



OF THE 



SALMONS OF THE PACIFIC COAST. 



Extracted from the Revised Edition of the Fish Manual. 
Pages 1 to 15, Plates 3 to 10. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1903. 




eh™ S H\b' 
Book S> i^tU fc 



/AS 



U. S. COMMISSION OF FISH AND FISHERIES, 

GEORGE M. BOWERS. Commissioner. 



ARTIFICIAL PROPAGATION 

3T& 



OF THE 



SALMONS OF THE PACIFIC COAST. 



Extracted from the Revised Edition of the Fish Manual. 
Pages 1 to 15, Plates 3 to 10. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1903. 






01 31190* 
D.otD,A 



Fish Manual. ( To faco page 1 .) 



Plate 3. 




THE SALMONS OF THE PACIFIC COAST. 



There are five species of salmon on the Pacific coast which belong 
to the genus Oncorhynchus, namely, the chinook or quinnat salmon 
(Oncorhynchus tschaicytscha), the red or blueback salmon (Oncorhynchus 
nerka), the humpback salmon (Oncorhynchus gorbuscha), the silver 
salmon (Oncorhynchus kisutch), and the dog salmon (Oncorhynchus Iceta). 
The features which separate the Pacific salmons from the Atlantic salmon 
are not marked and consist chiefly in a larger number of rays in the 
anal fin, and more branchiostegals, gillrakers, and pyloric cceca. 

The characters noted in the following key will usually be sufficient to 
distinguish the different species of Pacific salmon : 

Quinnat salmon : Scales in longitudinal series from 135 to 155, aver- 
aging about 145; pyloric cceca 140 to 185; gillrakers comparatively 
short and usually 23 in number, 9 being above the angle; rays in anal 
fin 16; branchiostegals 15 to 19. Body robust; head conic; eye small; 
caudal fin deeply forked. Color above dusky, sometimes with bluish or 
greeDish tinge; sides and belly silvery; head dark, with metallic luster; 
back and the dorsal and caudal fins with numerous round black spots. 

Blueback salmon: Scales in longitudinal series about 130; pyloric 
caeca, 75 to 95; gillrakers comparatively long and 32 to 40 in number; 
rays in anal fin 14 to 16; branchiostegals 13 to 15. Body rather slen- 
der; caudal fin much forked; anal and dorsal fins low. Color, above 
bright blue, sides silvery, no spots. 

Humpback salmon : Scales very small, 210 to 240 in lougitudinal series; 
pyloric cceca very slender, about 180 in number; gillrakers short, about 
28, 13 being above angle; anal rays 15; branchiostegals 11 or 12. 
Color, bluish above, silvery on sides ; hind part of back, adipose fin, and 
tail with numerous black spots, largest and of oblong form on tail. 

Silver salmon: Scales large, 125 to 135 in longitudinal series; pyloric 
cceca comparatively few and large, 45 to 80 in number; gillrakers long 
and slender, 23 in number, 13 below angle; anal rays 13 or 14; branchi- 
ostegals 13 or 14. Body long; head short, conic; snout blunt; eye 
small; fins small, caudal deeply forked. Color bluish- green, sides sil- 
very, finely punctulated; spots few and obscure on head, back, dorsal, 
adipose dorsal, and upper rays of caudal. 

Dog salmon : Scales of medium size, 138 to 155 in lateral line; pyloric 
cceca 140 to 185 ; gillrakers short and few, 9 above and 15 below angle ; 
13 or 14 rays in anal fin ; branchiostegals 13 or 14. Form of quinnat, 
but head longer and more depressed. Dusky above and on head, paler 
on sides; very fine spots on back and sides, often wanting; tail plain 
dusky or finely spotted, with black edge; other fins blackish. 

1 



2 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

These salmons are the most important group of fishes entering the 
rivers of North America. The steelhead (Salmo gairdneri), technically 
a trout, but popularly regarded as a salmon, also inhabits the waters ot 
the Pacific coast and adds to the importance of the salmon tribe. 

In recent years the annual catch of salmon in the Pacific States and 
Alaska has been over 100,000,000 pounds. In 1899 the quantity of 
salmon canned was 2,450,000 cases of 48 one-pound cans. The weight 
of the fresh fish represented by this pack, together with the large 
quantities sold fresh, salted, and smoked, was about 175,000,000 pounds, 
with a value, as placed on the market, of nearly $9,000,000. 

THE QUINNAT SALMON. 

The quinnat salmon (Oncorliynchus tschawytscha) is known by a 
number of other common names in various parts of its range; among 
them are chinook salmon, king salmon, Columbia salmon, Sacramento 
salmon, and tyee salmon. The quinnat is the most important of the 
salmons. It is not only superior in food qualities, but attains a vastly 
larger size, has a wider geographical range and a greater commercial 
value than any of the others. When fresh from the ocean it is a very 
handsome, resplendent, well-formed fish, greatly resembling the Atlan- 
tic salmon (Salmo solar), although its form is less symmetrical and its 
outlines less graceful. It is of a uniform rich red color, becoming paler 
or streaked upon the approach of the spawning season. Its value for 
canning purposes is largely enhanced by the persistence of the red color 
of the meat after cooking. 

In size no other salmon in the world compares with it. In the Yukon 
Eiver, Alaska, it reaches a weight of over 100 pounds, and in the 
Columbia River there are well authenticated cases of its weighing 
more than 80 pounds. Farther south, it runs smaller, although in the 
Sacramento individuals weighing 50 or 60 pounds are not rare; 22 
pounds is a fair average weight in the Columbia River and 16 pounds 
in the Sacramento. 

its known range is practically from Monterey Bay (latitude 36£) to 
the Yukon River, but individuals have been seen in Norton Sound, 
somewhat north of the Yukon, and as far down the coast of California 
as the Ventura River. Since itthrives well in very cold water it is likely 
that its range extends to and possibly within the Arctic Ocean. 

While in the sea quinnat salmon probably do not wander very far 
from the mouths of the rivers they have left, and for this reason usually 
return to spawn in the rivers in which they were hatched. They prefer 
the larger rivers, like the Sacramento, the Columbia, the Nushagak, 
and Yukon. They are very persistent in ascending the rivers to spawn, 
and have been seen crowding up the rivulets which form the head 
waters of the Sacramento until nearly half their bodies were exposed 
to the air. No matter how far the headwaters of a river are from the 
ocean, some of the salmon will press forward until stopped by impassable 
obstructions or water too shallow for them to swim in. On reaching 



MANUAL OF FISH-CULTURE. 3 

the headwaters they remain for a week or two before proceeding to the 
spawning grounds. Their rate of progress varies with the season, and 
probably depends to a great extent on the rainfall and the state of the 
river, rain, roily water, and high water always hastening their progress. 
When they first come from the ocean the sexes are almost identical 
in appearance, but as the time for spawning approaches a difference is 
noticed between the males and the females, which during the spawning 
season becomes more marked. The fully developed ova of the female 
give her a round, plump appearance, while the male grows very thin. 
His head flattens, the upper jaw curves like a hook over the lower, the 
eyes become sunken; large, powerful, white, dog like teeth appear on 
both jaws, and the fish acquires a gaunt and savage appearance. As 
soon as they reach fresh water their appetites grow less, their throats 
begin to narrow, and their stomachs to shrink. This does not at first 
entirely prevent them from feeding, but it changes them enough to 
enable them to overcome the temptation to return to their well-stocked 
feeding-grounds in the ocean, and the longer they remain in fresh water 
the greater are the changes, and the desire to turn back for food is 
correspondingly lessened. This change comes about gradually, increas- 
ing day by day from the time they leave tide water until at the near 
approach of the spawning season their throats and stomachs become 
entirely incapacitated for receiving food, and the desire and ability to 
feed leave them entirely. The great reserve of flesh and blood which they 
bring with them from the ocean enables them to keep the vital organs 
active until their mission up the fresh-water streams is accomplished. 

Quinnat salmon that spawn a long distance from the ocean do not 
return to it again, but die on or near their spawning-grounds. This 
singular fact has been disputed, but its truth has been proved repeat- 
edly and conclusively. After spawning they rapidly deteriorate, the 
flesh shades off to a light, dirty pink and they become foul, diseased, 
and much emaciated. Their scales are wholly absorbed in the skin, 
which is of a dark olive or black hue, and blotches of fungus appear on 
their heads and bodies, and in various places are long white patches 
where the skin is partly worn off*. Their fins and tails become badly 
mutilated, and in a short time they die exhausted. 

The quinnat salmon first appear on the Pacific coast at Monterey Bay, 
where many are caught with hook and line as early as the second week 
in January, and are next seen in the Sacramento River in numbers in 
February. In the Columbia River they appear in March, but are not 
abundant until April or May. They arrive in southern Alaska in 
/ May and farther north in June, while it is probable that it is still later 
before they ascend the Yukon, where the running seasou is very short 
and may not exceed a month or six weeks. The early runs in the 
Columbia River are usually from one to three weeks passing from the 
mouth of the river to Clifton, about 20 miles. They first appear a,z 
The Dalles, 200 miles up the river, in the middle of April, and are found 



4 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

in great quantities at this point about the middle of June, two months 
after they appeared in large numbers at the bar. This would indicate 
that they proceed up the Columbia at the rate of 100 miles a mouth. 
In the later runs they probably travel faster. 

The spawning season of the quinnat varies in different rivers and, 
considering the entire coast, lasts at least six months. In July the 
summer run is spawning at the headwaters of the McCloud and Sacra- 
mento rivers in California; in August and September, farther down 
these rivers. In October the fall run has begun in the McCloud and 
below and this run continues spawning through November into Decem- 
ber. In the Columbia the spawning begins at the headwaters in 
June; at Clackamas, 125 miles from the mouth of the river, it begins 
about the middle of September and continues until November. 

A few days before they are ready to spawn the salmon hollow out 
elongated cavities with their heads and tails in the gravel beds of the 
river where there is some current, and here in due time the eggs and 
milt are deposited. The eggs drift into the crevices in the pile of stones 
thrown up below the hollow, sink to the bottomland remain in that pro- 
tected position during incubation; here, also, the young remain until the 
umbilical sac is absorbed. The eggs and young are liable to destruction 
by freshets, but are comparatively safe from other injurious influences. 

The quinnat is not so prolific as the Atlantic salmon, 300 or 400 eggs 
to each pound weight of the parent fish being a fair average. 

In view of the enormous annual catch of this salmon for commercial 
purposes the necessity for its propagation became manifest at an early 
period in the history of the Pacific fisheries. Fortunately it is readily 
susceptible of artificial propagation on a large scale, otherwise the 
supply in the western rivers would have materially fallen off. Since 
the work began in 1873 on the McCloud Eiver it has grown to large 
proportions, and engages the attention of all the coast States as well as 
the General Government, and is now more extensive than ever before. 

As the salmon ascend the rivers they are caught by gill nets, fyke 
nets, pounds, weirs, seines, wheels, and other devices, but in the Sacra- 
mento and Columbia the greater numbers are caught with gill nets 
drifting with the current or tide as they head upstream. In the 
rivers they are comparatively safe from enemies except otters, ospreys, 
and fishers, but immense numbers are destroyed at the mouths of the 
streams by seals and sea lions. 

The quinnat salmon has been introduced into Japan, Australia, New 
Zealand, and Europe, but efforts to acclimatize it on the Atlantic coast 
of the United States have so far been unsuccessful. 

THE BLUEBACK SALMON. 

Considering the entire west coast, this species (Oncorhynchus nerlca) 
is probably more numerous than all the other salmons combined. It is 
known in different regions under the names blueback, redfish, red 
salmon, Fraser River salmon, and sock-eye or saw-qui. It ranks next 



F ; sh Manual. (To face page 5 



Plate 4. 




S 



MANUAL OF FISH-CULTURE. 5 

to the cbinook in commercial value, being especially important in the 
Columbia and Fraser rivers and in Alaska. For canning purposes it 
is but little inferior to the cbinook, the color of tbe flesh being a rich 
red, which persists after canning. Large quantities are canned in British 
Columbia and in Alaska, particularly on Kadiak Island, and its com- 
mercial importance to that Territory is indicated by the fact that nearly 
half of the entire salmon pack of tbe world comes from Alaska and the 
majority of the fish there canned are of tbis species. Comparatively 
few red salmon are sold fresh in the United States. 

It is next to tbe smallest of the salmons, the maximum weight being 
about 15 pounds, but it rarely weighs over 8 pounds and the average 
is scarcely 5 pounds. In various lakes this fish weighs only half a 
pound when mature, and is called the little redfish. 

It ranges from Humboldt Bay, California, to tbe far north. In gen- 
eral it ascends only those rivers which rise iu cold, snow-fed lakes. No 
more is known of its ocean life than of the quinnat. It appears in the 
Columbia with the spring run of the quinnat. In southern Alaska and 
at Kadiak Island it comes in numbers in June; tbe heaviest run is in 
June and July, the spawning occurring in August and September. In 
the Idaho lakes, which may be considered typical spawning-grounds 
for tbis fish in the United States, the height of the spawning season is 
from August 25 to September 5, although ripe eggs have been found as 
early as August 2, and fish with eggs in them as late as September 11. 
In the numerous affluents of the Fraser River the spawning extends 
from September 15 to November 15, a few stragglers spawning as late 
as November 30. They deposit their eggs on gravel in rather shallow 
water, usually in the inlets of the lakes. The eggs average about 1,000 
to 1,200 to the fish. 

Except in the breeding season the color of this fish is a clear bright 
blue above, with silvery sides and belly. At the spawning period tbe 
back and sides become red, and the male develops an extravagantly 
hooked upper jaw. 

THE HUMPBACK SALMON. 

The humpback salmon (Oncorhynchus gorbuscha) is the smallest of 
the Pacific salmons; its average weight is only 5 pounds, and it rarely 
reaches 10 pounds. Its range is from San Francisco probably as far 
north as the Mackenzie River, and it is also common on the Asiatic 
coast. It is the most abundant and generally distributed salmon in 
Alaska, but in the Pacific States it does not ordinarily occur in great 
abundance, although there is sometimes a noteworthy run in the Puget 
Sound region. 

In food qualities the fresh-run humpback is scarcely inferior to any 
other salmon. While the flesh has a very fine flavor, it is paler than that 
of other red salmon, and the species has consequently been neglected 
by canners; but it is probable that it will eventually be utilized for 
canning purposes, and its excellent qualities when fresh are undoubtedly 



6 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

destined to give it a great commercial value. Its chief consumption 
now is by Alaskan natives, who cure large quantities for winter use. 

The humpback salmon generally seeks the smaller streams tor the 
purpose of spawning and deposits its eggs a short distance from the 
sea, sometimes within only a few rods of the ocean. At Kadiak Island, 
Alaska, where it is often very abundant, it arrives in the latter part of 
July, the run continuing only a lew weeks. Spawning takes place in 
August. 

There are only a few hundred e£gs to each fish, the eggs being 
smaller than those of the quinnat but larger than those of the red fish, 
and paler in color than the eggs of either of those species. 

When this salmon first comes from the ocean it resembles a small 
quinnat, but as the spawning season advances it develops a very large 
and prominent hump on its back. This, with the distortion of the jaws, 
gives the fish a very singular appearance. The extreme emaciation and 
the extensive sloughing of the skin and flesh, which are incident to 
spawning, result in the death of all the hsh, either on the spawning- 
ground or after being swept out to sea by the current. 

THE SILVER SALMON. 

The silver salmon (Oncorhynchus Idsutch) is also known as silversides, 
skowitz, kisutch, hoopid salmon, and coho salmon. It is a beautiful 
fish, having a graceful form and a bright silvery skin. Its flesh, which 
is fairly good, usually has a bright red color, but as this fades on 
cooking it is not highly regarded for canning purposes, though large 
quantities are thus utilized on the Columbia River, Puget Sound, and 
the short coast streams of Oregon and Washington. Its average 
weight in the Columbia and Puget Sound is 8 pounds, but in Alaska it 
averages nearly 15 pounds; it rarely reaches 30 pounds. Its range 
is from San Francisco to northern Alaska, and as far south on the 
Asiatic coast as Japan. It runs up the rivers to spawn in fall or 
early winter, when the waters are high, but usually does not ascend 
great distances from the ocean. The average number of eggs to a fish 
is about 2,000. 

THE DOG SALMON. 

The dog salmon (Oncorhynchus keta) is the least valuable of the 
Pacific salmons, although it is dried in large quantities by the Alaskan 
natives. Its average weight is 12 pounds and the maximum is about 
20 pounds. It is found from San Francisco to Kamchatka, being 
especially abundant in Alaska. The enlargement and distortion of 
the jaws give the species a very repulsive look, and the large teeth 
give to it its common name. When just from the ocean, the flesh has 
a beautiful red color and is not unpalatable, but it deteriorates rapidly 
in freshwater. It spawns in shallow rivers and creeks. Larger quan- 
tities are utilized in Puget Sound than elsewhere in the Pacific States, 
and it is also used considerably by the natives of Alaska. 



Fish Manual. < To face page 7.) 



Plate 5. 




Fish Manual. (To face page 7.) 



Plate 6. 







I fl J>fc 



^y.:jf^* 




\?4 



MANUAL OF FISH-CULTURE. 7 

THE STEELHEAD. 

Another auadromous salmonoid fish found on the Pacific coast, popu- 
larly regarded as a salmon, is the steelhead (.Salmo gairdneri), known 
also as hardhead, winter salmon, square-tailed trout, and salmon trout. 
It resembles in form, size, and general appearance the salmon of the 
Atlantic coast, and is distinguished from other Pacific coast salmon by 
its square tail, its small head, round snout, comparatively slender form, 
light-colored flesh, and its habit of spawning in spring. It is more 
slender than the quinnat and consequently not so heavy for its length. 
Its average weight in the Columbia is about 10 pounds, although if 
sometimes reaches 30 pounds. 

Its range is very extended, reaching from Santa Barbara on the 
southern coast of California to the Alaska Peninsula, and perhaps to 
the Arctic Ocean, and it is found in almost all the streams of the 
Pacific States which empty into the ocean. It begins to enter the 
Columbia in the fall, and is then in prime condition. From this time it 
deteriorates until the following spring, when, between the months of 
February and May, spawning occurs. Its movements in other rivers 
on the coast are not materially different, though perhaps it enters the 
southern rivers earlier and northern rivers later than the Columbia. 
Like the chinook, the steelhead ascends rivers for long distances, and it 
has been found almost as far up the tributaries of the Columbia as the 
ascent of fish is possible. Its eggs are much smaller than those of the 
chinook and average 3,000 to 5,000 to the fish. 

As the greatest quantities of steelheads are caught in the spring, 
when they are spawning and are in a deteriorated condition, they are 
not generally esteemed as food ; but when they come fresh from the sea 
and are in good condition, their flesh is excellent. As the demand for 
salmon has increased, steelheads have been utilized for canning and 
they have formed a noteworthy part of the canned salmon from the 
Columbia River for a number of years past, as well as from the short 
coast rivers of Washington and Oregon. Their consumption fresh has 
been increasing yearly and considerable quantities have been sent to 
the Eastern States in refrigerator cars. 

ARTIFICIAL PROPAGATION. 

The chinook being the principal salmon that has been propagated 
artificially, the present chapter relates almost entirely to this species. 
The discussion of the apparatus and methods has special reference to 
the hatcheries of the Commission on McCloud River and Battle Creek, 
tributaries of the Sacramento, although cognizance is also taken of 
the work at the stations in the basin of the Columbia River and on 
the short coast rivers of California and Oregon. 

In 1899 the number of eggs of this fish collected by the Commission was 
48,043,000, from which about 43,775,000 fry were hatched and planted. 
The collections of steelhead eggs numbered 415,000, which produced 
85,935 fry. 



8 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

CAPTURING ADULT SALMON. 

The eggs used for artificial propagation are obtained from salmon 
taken on their way upstream to the natural spawning-grounds. The 
ascent of the fish is stopped by a heavy wooden rack or barricade and 
below this obstruction their capture is effected by various means 
depending on the natural conditions. At Baird station, on the McCloud 
River, the most practical method of collecting them in large numbers 
is with drag or sweep seines. These are from 120 to 170 feet long, 
made of about 28-thread twine, and are 20 feet deep in the middle, 
tapering down to about 6 feet at the ends; they are double-leaded on 
account of the swift current of the river, and have a 4-inch mesh. 

In the rack are built large wooden traps, in which at times (especially 
during a rain storm accompanied by a marked rise in the river) large 
numbers of salmon are taken, but there is never more than a small 
percentage of spawning fish thus secured. The trap is simply a square 
in closure of vertically placed slats, with an entrance similar to that of 
an ordinary pound net. The fish, in their eager efforts to pass upstream, 
go through the V-shaped mouth of the trap, and having once entered 
are not able to find their way out. Boards are placed over the top of 
the trap to prevent the fish from leaping out. 

The trap is quite a valuable auxiliary to the seine, but although it 
will secure many unripe fish, the ripe ones, which are the ones wanted, 
finding an obstruction in their way, are apt to settle back to spawning- 
grounds below and remain there. This may be obviated by building a 
second rack below the first, which, while permitting the ascent of the 
fish, is so constructed as to prevent their return. 

Large dip nets have been used occasionally at Clackamas station, in 
Oregon, the fishermen standing on the rack at night and dipping below 
it. Toward the end of the season this method secures a considerable 
number of ripe fish, but it involves much labor and expense, and most 
of the spawning fish taken with the dip nets would probably have been 
captured in the regular course of fishing. There being no satisfac- 
tory seining-grounds at Clackamas, and the river just below the rack 
being shallow, an Indian method of fishing is used. The aversion of 
salmon to heading downstream is well known, but when they are very 
much frightened they will turn around and rush downstream at their 
utmost speed. The Indians take advantage of this fact and build a 
dam of rock or wickerwork, or anything that will present an obstruc- 
tion to the frightened fish. It is shaped like the letter V, with the angle 
downstream, and at the angle is a large trap into which the fish are 
driven. This was at one time the principal method of capturing the 
breeding salmon at Clackamas, and it worked very satisfactorily. Fyke 
nets and other fish-catching devices have been employed from time to 
time, but have been rejected as unsatisfactory. 

At Baird, before the rack was employed permanently, seine fishing 
was usually begun after dark and continued throughout the night, but 



Fish Manual. (,To -face page 8.) 



Plate 7. 




MANUAL OF FISH-CULTURE. 9 

since the rack has been in use the seine has been hauled more or less 
in the daytime with perfectly satisfactory results, the fishing generally 
commencing about 4.30 a. m. and continuing as long as the results war- 
rant it. The work is resumed again about 5 o'clock in the afternoon 
and continued as long as it meets with success. 

CONSTRUCTION OF THE RACK. 

This obstruction consists of a fence placed across the river and sup- 
ported by piers heavy enough to prevent the force of the current from 
pushing them out of position. Log stringers, from 8 to 15 inches in 
diameter, are laid from pier to pier, to which they are securely pinned, 
and posts, from 2 to 4 inches in diameter and of the required length, 
are driven obliquely into the bed of the river, the lower ends being 3 
or 4 feet upstream, the upper ends resting on the stringers. Against 
these posts is laid the rack, which is made in sections, each 6 to 10 feet 
long, the slats which form them being 1^ inches thick and 3 inches 
wide, and securely braced at top and bottom. The slats are set 1£ 
inches apart, and are beveled on the upper side in order to present less 
resistance to the current. The space between the slats allows ample 
room for water to go through, but j^revents any.salmon from ascending. 
A wider space between the slats would be preferable, as creating less 
obstruction to the current, but it would allow a considerable percent- 
age of small grilse (the young salmon after its first return from tbe sea) 
to get by the rack, and unless the older males are quite plentiful the 
grilse are likely to be needed when the spawning season arrives. 

The piers, when first made, are hollow triangles of heavy logs, each 
layer of logs being firmly pinned to the one below it, until the required 
height is reached, the apex of the triangle pointing upstream. They 
are afterwards filled with rocks and are very substantial. Those on 
the McCloud have been able to withstand the tremendous momentum 
of the current, even in the highest water. 

TAKING AND IMPREGNATING THE EGGS. 

After salmon are secured by the seine or other means, they are, for 
convenience in handling, placed in pens or live-boxes made for this 
purpose, the ripe or nearly ripe males and females being kept separate. 
Where the eggs are taken on a large scale, it is desirable to have 
separate compartments for ripe males, ripe females, nearly ripe females, 
and males partially spent that it may be necessary to use again, and 
one or two spare compartments are found to be convenient where large 
numbers of fish are handled. 

Stripping the fish is usually done every day, as the eggs of the females 
confined in the pens are likely to be injured within the fish, which is a 
serious objection to keeping the parent fish in confinement any longer 
than is absolutely necessary. 

Of the signs that usually accompany ripeness in a female salmon, 
the separation of the eggs in the ovaries is the surest, but the spawn- 



10 REPORT OF COMMISSIONER OP FISH AND FISHERIES. 

taker relies rather on a general appearance which is neither color, 
shape, nor condition of organs, but which shows at a glance that the 
fish is ripe and can be appreciated only by experience. 

Spawning operations arc conducted upon a floating platform, beneath 
which are compartments for retaining the ripe fish, and which are 
accessible through hinged covers set in the plank flooring. Projecting 
beyond this platform is another, upon which the actual work of strip- 
ping the fish and caring for the pans is performed. 

When taking the eggs, one or two men stand ready with dip nets to 
hand the females to the spawn-taker, and one or more perform the same 
office with the males. After the salmon are taken from the pens they 
are held suspended in the net until their violent struggles are over, 
after which they become quiet enough to be handled and the eggs and 
milt can be expressed easily. 

All methods of taking salmon spawn are very much the same, there 
being only slight differences in details, chiefly in the manner of holding 
the parent fish and impregnating the eggs. Where there are plenty 
of assistants and the salmon are of medium size, the most expeditious 
way is for the man who takes the spawn to hold the female in one 
hand and press out the eggs with the other, another in the meantime 
holding the tail of the fish. The male is handled in the same way. 

The above method is employed at Baird, but on the Columbia River, 
where the salmon are larger and are harder to manage, the "strait- 
jacket," as it is called, is used; this is a sort of a trough made about 
the average length of the salmon and hollowed out to fit its general 
shape. Across the lower end is a permanent cleat, and at the upper end 
is a strap with a buckle. The fish, when manipulated, is slid into the 
trough, the tail going down below the cleat, where it is securely held, 
and the head is buckled m at the upper end with the strap. It is now 
unable to do any harm by its struggles and the eggs can be pressed 
out at leisure. The strait-jacket is almost indispensable with the very 
large salmon and is a very great convenience when the operators are 
limited in number. 

In impregnating the eggs the main object is to bring the milt and 
the eggs together as quickly as possible after they have left the fish. 
By some persons a little water is considered desirable to give greater 
activity to the milt, but if left more than a minute in the water there 
is a decided loss of fertilizing power. The eggs do not suffer so quickly 
from immersion in water. The absorbing property which they possess 
when they first leave the parent fish, and which attracts to the 
micropyle the spermatozoa, lasts several minutes, but it is not prudent 
to leave the eggs in the water a moment longer than is necessary before 
adding the milt. 

The addition of the water is not essential to a good impregnation; 
in some instances better results are secured without the use of water 
and, after all, if the main object is secured, of bringing the milt and 



Fish Manual. (To face page 10.) 



Plate 




TAKING SALMON EGGS AT LITTLE WHITE SALMON STATION. 




FERTILIZING SALMON EGGS. 




SALMON IN STRAIT-JACKET. 



MANUAL OF FISH-CULTURE. 11 

the eggs together with the slightest possible delay after they leave the 
fish, it makes very little difference whether water is used or not. 
The milt retains its fertilizing power several days when kept from air 
and water, and impregnation can be effected between fishes widely 
separated by merely forwarding the milt properly sealed. At Baird 
impregnation by the dry method, which has always been followed there, 
has resulted in the fertilization of about 90 per cent of the eggs so treated. 

The Eussian or dry method of impregnating eggs consists simply in 
taking both the eggs and the milt in a moist pan. It may be urged as 
an objection to this method that the eggs will be injured by striking 
against the pan, but it is a fact that although the same eggs would be 
destroyed by the concussion a week later, or even 24 hours later, they 
do not suffer in the least from it at the moment of extrusion from the 
fish. 

It was at one time considered an important question whether the 
eggs or milt should be taken first, but with the dry method it makes 
no difference, as, either way, both eggs and milt remain operative long 
enough for all practical purposes of impregnation. 

Various methods of treating the eggs in the pan after impregnation 
has taken place have been tried. Some operators leave the eggs in 
the pans as first taken with the milt for two or three minutes and then 
add water, after which they are left to stand in the pan until they 
separate, when they are washed clean, taken to the hatching-house, and 
placed in the troughs. Others pour the contents of the several pans — 
eggs, milt, and all — into a large can after the eggs become impregnated, 
and when the eggs separate the contents of the can are poured into the 
hatching-troughs, trusting to the current in the troughs to wash the milt 
from the eggs. At Baird, water is poured on the eggs a few moments 
after they become impregnated, after which they are left perfectly quiet 
until they separate, which in watenof the temperature of the McCloud 
River in September, 52° to 53°, takes about an hour. The pans, in the 
meanwhile, are put in a trough filled with river water to keep them 
from becoming too warm. After the eggs separate they are carefully 
washed and are carried in buckets to the hatching-house, where they 
are measured an d placed in the hatching-trays. 

The methods of taking and fertilizing eggs at Clackamas are as follows : 
The female fish to be operated upon is taken from a floating pen and 
is placed in the spawuiug box or "strait-jacket"; a male fish is then 
caught and tied with a small rope around its tail to some part of the corral 
where he can be quickly caught when needed. One man presses the 
eggs from the female securely held in the spawning-box, the pan for 
receiving these being held by another. As soou as the eggs are taken, 
the male is drawn from the pen by the rope and held by one man, who 
takes it by the tail with his left hand, its head between or across his 
kuees. With his right hand the milt is then pressed from the fish 
into the pan containing the eggs as soon as possible after they are taken. 



12 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

The eggs are taken in a pan without any water and milt enough is 
used to insure its coming in contact with each egg. After the eggs and 
milt are obtained the pan is gently tilted from side to side and the mass 
of eggs and milt stirred with the fingers until thoroughly mixed. The 
pan is then filled about two-thirds full of water and left until the eggs 
separate, the time varying from 1 to li hours, according to the number 
of eggs and the condition of the atmosphere. 

The eggs of the quinuat salmon are of a deep salmon-red color and are 
heavier than water. In size they average about -^ or -^ of an inch, 
from 12 to 18 being covered by a square inch. The number in a quart 
is about 3,700. Probably 90 per ceut of the eggs taken are impregnated 
on an average, though the results vary with different seasons, places, 
and methods of handling. 

HATCHING APPARATUS AND METHODS. 

The hatching apparatus generally employed on the Pacific coast in 
salmon propagation consists of a combination of troughs and baskets. 
The troughs in common use are the so-called " Williamson troughs," 
which are 16 feet long, 12 or 1G inches wide, and 0i inches deep. The 
troughs are arranged in pairs, and usually two or three pairs are placed 
end to end on different levels. The fall of water in each trough is 1£ 
inches. The troughs are divided by double partitions of wood or metal 
into compartments just enough longer than the baskets to enable the 
latter to be raised and lowered and to be tilted slightly. The essential 
feature of these troughs is that at the lower end of each compartment a 
partition, extending entirely across the trough, reaches from the bottom 
almost to the top, and another similar partition at the upper end of the 
compartment reaches from the top almost to the bottom of the trough, 
each set of partitions being about an inch apart. The water is conse- 
quently forced to flow under the upper partition and over the lower 
partition, and to do this it must necessarily ascend through the tray 
of eggs. The troughs are provided with canvas covers stretched upon 
light frames, and made sunlight proof by saturation with asphaltum 
varnish, and their interiors are thickly coated with asphaltum. 

The egg receptacles are wire trays or baskets about 12 inches wide, 
24 inches long, and deep enough to project an inch or two above the 
water, which is 5 or inches deep in the troughs in which they are 
placed. Into each of these baskets 2 gallons of salmon eggs, equiva- 
lent to about 30,000, are poured at a time. The eggs suffer no injury 
whatever from being packed together in this manner, the water being 
supplied in a way that forces it through the eggs, partially supporting 
and circulating through them. The meshes are too small to permit the 
eggs to pass through, although the fry are able to do so. 

The advantages of this apparatus and method are: 

(1) The top. of the tray or basket is out of the water and always 
entirely dry ; consequently, in handling it, the hands are kept dry. 



Fish Manual. (To face page 1 2 ) 



Plate 9. 




MANUAL OF FISH-CULTURE. 13 

(2) By tilting one end of the tray up and down a little or by lifting 
it entirely and settling it gently back again in its place the bad eggs 
will be forced to the top; thus a feather is not required in picking over 
the eggs and the injuries very often inflicted with it are avoided. 

(3) The top of the tray being above water, the eggs can never run 
over the top nor escape in any way, which is a great advantage over 
the shallow form of tray. 

(4) There is economy of space; 30,000 to 40,000 eggs can be placed 
in each basket, provided a sufficient quantity of water is available. 
Two troughs, 10 feet long and 1 foot wide, will by this method carry 
about 500,000 salmon eggs. The deep trays may be filled at least half 
full of eggs, and thus ten times as many eggs can be hatched in the same 
space and with the same supply of water as by the old method. A 
good but gentle circulation is continually maintained through the eggs. 

(5) The deep-tray system is admirably adapted to getting rid of mud 
that has collected on the eggs, for all sediment accumulating about 
them can be easily removed by gently moving the tray up and down a 
few times in the water; but if the deposit of mud on the troughs 
becomes so excessive as to be unmanageable, a false bottom of wire 
cloth or perforated zinc can be placed in the troughs at a suitable 
distance above their real bottom, leaving a space of about 1 or 1£ inches 
between the wire cloth and the trough bottom. By this means the mud 
that comes into the trough will sift down into the space below the wire 
cloth entirely out of the way of the fish, the movements of the fish 
themselves helping very much to produce this result. Should the 
accumulation of mud in the space below the false bottom of the trough 
become too great, it can easily be sluiced out in various ways. 

When quinnat-salmon eggs are simply to be matured for shipment, 
hatching trays with |ori inch square mesh will answer the purpose, 
but when the eggs are to be hatched in them, every alternate strand 
of wire running lengthwise, or, better still, every second and third 
thread should be left out in order to form an oblong mesh through which 
the newly hatched fry, after separating themselves from the unhatched 
eggs, can escape from the hatching trays into the trough belpw. 

AtBaird eggs kept in water averaging about 54° F, hatch in 35 days. 
The allowance of 5 days' difference in the time of hatching for each 
degree of change in the water temperature is approximately correct. 

For the first few days the eggs of the quinnat salmon are very hardy, 
and at this time they should be thoroughly picked over and the dead 
ones removed as far as possible before the delicate stage during the 
formation of the spinal column comes on, so that during that critical 
period they may be left in perfect quiet. As soon as the spinal column 
and the head show plainly, the eggs are hardy enough to ship, but when 
there is time enough it is better to wait a day or two until the eye-spot 
is distinctly visible, after which time the eggs will stand handling and 
may be safely shipped if properly packed. 



14 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

PACKING EGGS FOR SHIPMENT. 

The packing-box used in shipping salmon eggs is made of £-inch 
pine, 2 feet square and 1 foot deep. At the bottom is placed a thick 
layer of moss, then a layer of mosquito netting, then a layer of eggs, 
then mosquito netting again, then successive layers of moss, netting, 
eggs, netting, and so on to the middle of the box. Here a firm wooden 
partition is fastened in and the packing renewed above in the same 
manner as below. The cover is then laid on the top, and when two 
boxes are ready they are placed in a wooden crate, made large enough 
to allow a space of 3 inches on all sides of the boxes. This space is 
filled with hay to protect the eggs against changes of temperature, and 
the cover being put on the eggs are ready to ship. In the middle of 
the crate an open space about 4 inches in depth is left, between the 
two boxes of eggs, for ice. As soon as the crates arrive at the railway 
station this space, as well as the top of the crate, is filled in with ice. 
Recent experiments show that salmon eggs can be packed and safely 
transported to considerable distances when they are first taken. 

CARE OF THE FRY. 

The eggs of quinnat salmon, like those of the other Salmonidce, hatch 
very gradually at first, only a small proportion of fish coming out the 
first day; but the number increases daily until the climax is reached, 
when large numbers of young burst their shells in a single day. At 
this time great care and vigilauce are required. The vast numbers of 
shells rapidly clog up the guard-screens at the outlets of the troughs, 
which should be kept as free as possible by thoroughly cleansing them 
from time to time. 

In the deep trays the newly hatched fish are mixed with unhatched 
eggs, and the advantage of the oblong mesh in the bottom of the trays 
becomes apparent. This mesh is too narrow to allow the eggs to fall 
through, but the hatched fish, being comparatively long and narrow, 
easily slip down through the long meshes into the space below. They 
should be assisted by gently raising and lowering the tray at intervals, 
care being taken not to raise them out of the water, as at this tender 
age a slight pressure against the wire of the tray will often produce 
fatal injuries. On this account too much caution can not be exercised 
in regard to handling them out of water during the first stages of the 
yolk-sac period, for the injuries can not be seen at first, and often the 
death of the fry is the first warning that they have been injured. 

After the eggs are all hatched and the young fish are safely out of 
the trays and in the bottom of the troughs, their dangers are few and 
they require comparatively little care. Almost the only thing to be 
guarded against now is suffocation. Even where there is an abun- 
dance of water and room, with a good circulation, they often crowd 
together in heaps or dig down under one another until some of them die 
from want of running water which is not an inch away from them. The 
best remedy in such a case is to thin them out. 



Fish Manual. (To face page 14.) 



Plate 10- 




MANUAL OF FISH-CULTURE. 15 

Eight thousand gallons of water an hour is sufficient for ten lines of 
troughs 64 feet in length, containing altogether a little over 1,000,000 
young salmons in the yolk-sac stage. This gives in round numbers 
800 gallons of water to each 100,000 fry every hpur, or 16§ gallons per 
minute, which is a safe minimum. 

FEEDING AND PLANTING THE FRY. 

When the yolk-sac has become nearly absorbed the fish rise from 
the bottom of the trough, where they have previously remained, and 
begin swimming. They are now almost ready for food and must be liber- 
ated unless artificial food is provided. As a rule the fry are planted 
about the time the yolk-sac is absorbed. This is regarded as the best 
practice, and moreover the amount of space required renders the rearing 
of fry in large numbers impracticable. They have, however, been suc- 
cessfully retained in troughs in small numbers from the time they begin 
to feed in February until the middle of May, when on account of the 
rising temperature of the water they are liberated. They show when 
they are ready to feed by darting to one side or the other when small 
particles of food are dropped in the water and floated past them. From 
this time, for several weeks, the necessity for care and vigilance never 
ceases. For the first few weeks they should be fed regularly and as 
often as six times a day, and the earlier in the day the feeding begins 
and the later it continues at night the better. Two hours after feeding 
they will be found to be ravenously hungry, and they grow much faster 
for frequent feeding and get that growth in their infancy which is 
indispensable to their ultimately attaining the largest possible size. If 
not fed sufficiently they will bite at one another and cause more or less 
mortality among themselves. 

The best food for salmon fry is some kind of meat, finely pulverized. 
Boiled liver is especially good for this purpose, partly because it is 
inexpensive and easily obtainable, and also because it can be separated 
into very fine particles. Raw liver is also excellent and may be reduced 
into as fine particles as the cooked liver by grinding or chopping and 
then properly straining it through a fine-mesh screen. The yolk of 
boiled eggs is also suitable, but is much more expensive than liver and 
is not so good for the fish as liver, unless largely mixed with it. 

As the fish grow older they continue to thrive best on meat food, but, 
if that is not always obtainable in sufficient quantities or on account 
of its expense, a very good substitute is a mixture of shorts or corn 
meal with the meat. This is prepared as a mush by stirring shorts or 
middlings into boiling water, a little at a time, so that it will not cook 
in lumps, but become more of a paste. After it has thoroughly cooked 
it is allowed to cool and harden. The best proportion is 30 pounds of 
shorts to 25 gallons of water with 3 or 4 pounds of salt. The per- 
centage of liver to be used in this mixture should be regulated by the 
age of the fish, feeding the very young fry upon almost a simple meat 
diet and gradually increasing the proportion of mush. 











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